1. Field of the Invention
This invention pertains to the domain of material handling and relates more particularly to a pack of the type comprising a plurality of superposed layers or tiers of unit loads and at least one strap encircling said plurality of layers.
The present invention is applicable notably but not exclusively to packs of which the unit loads consist of bags filled with loose material. In many cases unit loads of this type must be stored in large quantities in warehouses before actually distributing and utilizing them. As a rule, the bags are transported by road or railroad trucks to the warehouse where they are subsequently discharged and re-grouped to form packs comprising each a plurality of superposed layers or tiers of bags, each pack being bound by means of at least one strap. Each pack thus formed is picked up and transported by a lift truck to the storage place proper where the packs are laid side by side and superposed to constitute a stack comprising several contiguous "walls", each wall comprising several contiguous columns of packs.
2. Description of the Prior Art
As a rule, packs of this character are handled by using pallets or a special pick-up system. In this last case, to prevent the packs from getting loose during the handling and to allow handling thereof with the maximum safety, the strap or straps encircling the pack must be extremely tight, so that the unit loads constituting such pack form a compact, tight assembly. As a result, the inner and upper surfaces of the packs tend to assume a convex shape, thus impairing the stability of the columns formed thereby. It follows that only four or five packs can be stacked in each column. Moreover, the upper packs in each column must be chocked up in most cases and this operation requires the presence of several persons on top of the stacks for chocking up the unstable packs. Now, this not only increases the number of hands necessary for performing the handling operations but also aggravates the danger of falling for the persons working on top of the stack, considering the lacks of stability of the columns. Moreover, since the height available in warehouses is much greater than the height of the columns of packs that can be made with hitherto known pack arrangements, a valuable vertical space is lost without profit.
It is the main object of the present invention to avoid the inconveniences disclosed hereinabove by providing a pack having a particular structure such that a relatively large number of such packs can be superposed to form a column of great height and great stability without resorting to pallets or the like.
Another object of the invention is to provide a machine for making such packs.